1. Field of the Invention
The present invention relates to solid phase-fixed dithiolanylium salts and dithianylium salts and ylidene-dithianes and ylidene-dithiolanes, to the preparation thereof and to the use thereof.
2. Discussion of Background Information
Dithianes or dithiolanes and their oxo derivatives are known from the prior art. For example, U.S. Pat. No. 4,946,861 describes dithianylidenes and the oxides thereof and the use thereof as pharmaceuticals.
It is known that dithianes or dithiolanes can be used for the conversion of ketones or aldehydes. This affects applications including the following:
1) as protecting groups in protecting group strategies
2) as a necessary transformation in the umpolung reaction
3) as an intermediate for further derivatization, for example introduction of fluorine.
The transformation of the carbonyl functionality to give the dithiolane and to give the dithiane is a reaction that can be conducted with good to very good yields, but which generally has the following disadvantages:
1) the reagents are toxic
2) the reagents stink to high heaven
3) the products have to be purified in a complex manner after the reaction
4) many reactions are not possible or run poorly, since the acid breaks down acid-labile groups in solution.
Synthetic Communications, Vol. 34, No. 24, pages 4545-4556, 2004 discloses use of 2-[1,3]dithian-2-ylidene-3-oxobutanamide as thioacetalization reagent in liquid phase reactions, wherein the workup of the products always also includes a chromatographic purification.
In the form of 2-(1,3-dithian-2-ylidene)malonic acid, Synthetic Communications, Vol. 37:6, pages 993-1000, 2007 discloses a similar substance for thioacetalization in liquid phase reactions.
What is common to the prior art is that the compounds disclosed are in unbound, i.e. unfixed, form and the reactions accordingly proceed entirely in liquid phase. Correspondingly, the disadvantages mentioned occur.